Field of the Invention
The present disclosure relates to a ventilating fan, in particular to a ventilating fan with a humidity sensor.
Description of the Related Art
In order to make the ventilating fan run automatically according to the change of ambient environment, the existing ventilating fan is generally equipped with a body sensor, a humidity sensor, a carbon monoxide sensor and the like, and real-time detection to the ambient environment is performed by the various sensors, and the ventilating fan is controlled to turn on/off or change operation speed, according to the detecting result, such as a ventilating fan with a humidity sensor as described in China utility model patent ZL201320384615.X.
FIG. 1 is a schematic structural view of a ventilating fan in the conventional art. As shown in FIG. 1, the conventional ventilating fan comprises: a frame 1 provided with an opening 4 at an indoor side, a casing 2 provided in the frame 1, an air blower 3 provided in the frame 1, and a humidity sensor provided in the casing 2. When the humidity sensor detects that the indoor air reaches certain humidity, the air blower 3 of the ventilating fan will automatically run so as to discharge the indoor moist air to the outdoors and thus achieve the purpose of dehumidification.
When the ventilating fan with the humidity sensor is placed in a hot and humid environment like a bathroom, in order to prevent the water vapor in the air from being liquefied into water droplets and being collected on the humidity sensor or prevent the shower water from splashing on the humidity sensor which may results in a short life expectancy and a low sensing accuracy for the humidity sensor, the humidity sensor will generally be disposed in a waterproof box 5.
An air inlet is provided in a bottom surface 7 of the waterproof box 5 facing the inside of the room, and the air outlet is provided in a side surface 6 adjacent to the bottom surface. When the indoor air is sucked by the air blower, a part of the air enters the waterproof box 5 through the air inlet, comes into contact with the humidity sensor in the waterproof box 5, and then is discharged through the air outlet.
Under the drawing of the air blower 3, the air enters the waterproof box 5 from the air inlet on the bottom surface 7 facing the inside of the room, and then the direction thereof is required to be changed so as to be discharged out of the waterproof box 5 from the air outlet in the side surface 6 adjacent to the bottom surface 7. The air abounds with water vapor, and is liable to be detained in the waterproof box 5 during the flow process and may not be taken out. So even if the indoor humidity has been reduced, but due to the water vapor inside the waterproof box 5, the humidity sensor may still detect a high humidity, resulting in a continuous operation of the ventilating fan. In other words, the humidity sensor has a decreased sensing accuracy, and may not accurately or precisely detect the indoor humidity.